Retread determination device, retread determination method, and retread determination program

Abstract

This retread determination device comprises: a collection unit that collects use history data relating to a use history after a tire has been mounted on a vehicle; a calculation unit that calculates a remaining durability value on the basis of the correspondence relationship between a tire fatigue degree that accumulates according to the use history data and tire use time or travel distance, the remaining durability value being the time or distance until the current fatigue degree of the tire reaches a fatigue degree limit value that is set in advance according to the performance of the tire; a determination unit that determines whether or not to retread the tire on the basis of the remaining durability value and the remaining tire life, which is the remaining time or distance until the tread thickness of the tire becomes equal to or less than a predetermined value; and a notification unit that provides notification as to whether or not to retread the tire on the basis of the determination result.

Description

Retread Determination Device, Retread Determination Method, and Retread Determination Program

[0001] The present disclosure relates to a retread determination device, a retread determination method, and a retread determination program.

[0002] A pneumatic tire is made by attaching tread rubber that contacts the road surface to a case composed of a carcass, a belt, an inner liner, a sidewall, etc. The case can often withstand sufficient use even after the tread rubber has reached the end of its life. Therefore, a new tread rubber is attached (retreaded) to the case of a tire whose tread rubber has worn due to use, and it is reused as a retreaded tire (regenerated tire) (see, for example, Japanese Patent Application Laid-Open No. 2009-190377). Retreading of tires is utilized as a method for efficiently using tires and reducing the cost of purchasing new tires.

[0003] However, depending on the condition of the case, it may not be possible to drive as expected after retreading, and the cost of retreading may not be recovered. Therefore, it is desired to appropriately determine whether retreading of a tire is necessary.

[0004] An object of the present disclosure is to provide a retread determination device, a retread determination method, and a retread determination program that can appropriately determine whether retreading of a tire is necessary.

[0005] To achieve the above objective, the first embodiment is a retreading determination device comprising: a collection unit that collects usage history data relating to the usage history of a tire since it has been mounted on a vehicle; a calculation unit that calculates a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of the fatigue level according to the performance of the tire, based on the relationship between the tire fatigue level accumulated according to the usage history data and the tire usage time or mileage; a determination unit that determines whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tread thickness of the tire falls below a predetermined value; and a notification unit that notifies whether or not the tire should be retreaded based on the determination result from the determination unit.

[0006] The second embodiment is a retread determination device according to the first embodiment, wherein the determination unit obtains the remaining tread thickness, which is the tread thickness currently remaining on the tire; the retread life, which is the remaining time or distance until the tread thickness of the tire falls below a predetermined value after the tire has been retreaded; the tire cost, which is the cost per tire; and the retread cost, which is the cost of retreading the tire. Based on the remaining durability value, the remaining tire life, the remaining tread thickness, the retread life, the tire cost, and the retread cost, the determination unit determines whether or not the tire should be retreaded.

[0007] A third embodiment is a retread determination device according to the second embodiment, further comprising a determination unit that, when the determination unit determines that the tire should be retreaded, determines the tread thickness necessary to satisfy the retread life from the remaining durability value.

[0008] The fourth embodiment is a retread determination device according to the third embodiment, wherein the determination unit calculates the cost per unit time or unit distance from the remaining durability value, the remaining tire life, the remaining tread thickness, the retread life, the tire cost, and the retread cost, and determines the timing of the retread and the tread thickness based on the calculated cost per unit time or unit distance.

[0009] The fifth aspect is a retreading determination method in which a computer performs the following processes: collects usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculates a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of fatigue level according to the tire's performance, based on the relationship between the tire's fatigue level accumulated according to the usage history data and the tire's usage time or mileage; determines whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tire's tread thickness falls below a predetermined value; and notifies whether or not the tire should be retreaded based on the determination result.

[0010] The sixth aspect is a retreading determination program that causes a computer to perform the following processes: collect usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculate a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of fatigue level according to the tire's performance, based on the relationship between the tire's fatigue level, which is accumulated according to the usage history data, and the tire's usage time or mileage; determine whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tire's tread thickness falls below a predetermined value; and notify the computer whether or not the tire should be retreaded based on the determination result.

[0011] This disclosure has the effect of enabling appropriate determination of whether or not tire retreading is necessary.

[0012] This figure shows an example of the configuration of a retreading determination system according to an embodiment. This block diagram shows an example of the functional configuration of a retreading determination device according to an embodiment. This figure shows an example of usage history data and tools. This graph shows an example of the correspondence between the tire fatigue level of each tire and the total tire life. This flowchart shows an example of the processing flow by the retreading determination program according to an embodiment.

[0013] Embodiments of the technology described herein will be described in detail below with reference to the drawings. Components and processes that perform the same function or operation will be given the same reference numerals throughout the drawings, and redundant explanations may be omitted as appropriate. Furthermore, this disclosure is not limited in any way to the embodiments described below, and can be implemented with appropriate modifications within the scope of the purpose of this disclosure.

[0014] The retread determination device according to this embodiment collects usage history data relating to the usage history of a tire since it was mounted on a vehicle. Based on the relationship between the tire fatigue level accumulated according to the usage history data and the tire usage time or mileage, it calculates the remaining durability value, which is the time or distance until the current tire fatigue level reaches a predetermined fatigue limit value according to the tire's performance. Based on the remaining durability value and the remaining tire life, which is the time or distance remaining until the tire tread thickness falls below a predetermined value, it determines whether or not the tire should be retreaded and notifies the user whether or not the tire should be retreaded based on the determination result. By using the remaining durability value and the remaining tire life, it is possible to appropriately determine whether or not a tire needs to be retreaded.

[0015] Figure 1 shows an example of the configuration of the retreading detection system 100 according to this embodiment.

[0016] As shown in Figure 1, the retreading detection system 100 according to this embodiment includes a retreading detection device 10 that performs retreading detection and a terminal device 20 used by the user of the vehicle 21. The retreading detection device 10 and the terminal device 20 are connected to communicate via a network N. The network N is, for example, a communication network such as the Internet, LAN (Local Area Network), or WAN (Wide Area Network). The retreading detection device 10 is, for example, a general-purpose computer device such as a server computer or a personal computer (PC). The terminal device 20 is, for example, a terminal device such as a smartphone, tablet terminal, or PC.

[0017] The terminal device 20 is connected to the vehicle 21 in a communication manner and acquires sensor information obtained from sensors 22 installed on the vehicle 21. The sensor information includes, for example, driving speed, acceleration / deceleration / lateral G-force, steering angle, load, and tire pressure.

[0018] The retreading detection device 10 according to this embodiment includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an input / output interface (I / O) 14, a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18.

[0019] The CPU 11, ROM 12, RAM 13, and I / O 14 are connected to each other via a bus. The I / O 14 is connected to various functional units, including a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18. These functional units are capable of communicating with the CPU 11 via the I / O 14.

[0020] The control unit is comprised of a CPU 11, ROM 12, RAM 13, and I / O 14. The control unit may be configured as a sub-control unit that controls the operation of a part of the retreading detection device 10, or as part of a main control unit that controls the operation of the entire retreading detection device 10. Integrated circuits or IC chipsets, such as LSIs (Large Scale Integrations), are used in part or all of each block of the control unit. Individual circuits may be used for each of the above blocks, or circuits that integrate part or all of them may be used. The above blocks may be provided as a single unit, or some of the blocks may be provided separately. Furthermore, a part of each of the above blocks may be provided separately. For the integration of the control unit, dedicated circuits or general-purpose processors may be used, not limited to LSIs.

[0021] For example, the storage unit 15 can be an HDD (Hard Disk Drive), an SSD (Solid State Drive), or flash memory. The storage unit 15 stores a retreading determination program 15A for executing the retreading determination process according to this embodiment. This retreading determination program 15A may also be stored in the ROM 12.

[0022] The retreading detection program 15A may, for example, be pre-installed in the retreading detection device 10. The retreading detection program 15A may also be implemented by storing it on a non-volatile storage medium or distributing it via a network N and installing it on the retreading detection device 10 as appropriate. Examples of non-volatile storage media include CD-ROM (Compact Disc Read Only Memory), magneto-optical disk, HDD, DVD-ROM (Digital Versatile Disc Read Only Memory), flash memory, memory card, etc.

[0023] The display unit 16 may use, for example, a liquid crystal display (LCD), an organic EL (Electroluminescence) display, or the like. The display unit 16 may also have an integrated touch panel. The operation unit 17 is equipped with, for example, a keyboard, mouse, or other device for operation input. The display unit 16 and the operation unit 17 receive various instructions from the user of the retreading detection device 10. The display unit 16 displays various information such as the results of processing performed in response to the instructions received from the user, and notifications regarding the processing.

[0024] The communication unit 18 is connected to a network N such as the Internet, LAN, or WAN, and is capable of communicating with the terminal device 20 via the network N.

[0025] In this embodiment, the CPU 11 of the retreading detection device 10 functions as shown in Figure 2 by writing the retreading detection program 15A stored in the ROM 12 or memory unit 15 to the RAM 13 and executing it.

[0026] Figure 2 is a block diagram showing an example of the functional configuration of the retreading determination device 10 according to this embodiment.

[0027] As shown in Figure 2, the CPU 11 of the retreading determination device 10 according to this embodiment functions as a collection unit 11A, a calculation unit 11B, a determination unit 11C, a notification unit 11D, and a decision unit 11E.

[0028] The collection unit 11A collects usage history data regarding the usage history of the tires since they were mounted on the vehicle 21.

[0029] Figure 3 shows an example of usage history data and tools. Usage history data includes, for example, thermal history during driving, mileage, load, remaining tread amount / installation history, and vehicle information.

[0030] The thermal history during driving is acquired, for example, using a TPMS (Tire Pressure Monitoring System). A TPMS is a system that uses sensors attached to the tires to monitor the internal pressure, internal temperature, etc., of the tires while driving.

[0031] The mileage is obtained, for example, using GPS (Global Positioning System). However, iTrack (registered trademark: Mining Vehicle Tire Monitoring System) may be used instead of GPS. iTrack is a system that integrates and manages data such as tire pressure, internal temperature, vehicle location information, and driving speed.

[0032] The load is obtained, for example, using an FMS (Fleet Management System). An FMS is a system that manages the load on the tire, etc. However, if it is possible to predict from the change in tire pressure, a TPMS may be used instead of an FMS.

[0033] The remaining tread depth (remaining groove depth) and installation history are obtained, for example, using a TMS (Tire Management System). A TMS is a system that manages information such as vehicle information, tire installation history, and the remaining tread depth of the tires.

[0034] The calculation unit 11B calculates the remaining durability value based on the relationship between the tire fatigue level, which is accumulated according to the usage history data collected by the collection unit 11A, and the tire usage time or mileage. The remaining durability value is the time or distance until the tire's current fatigue level reaches a predetermined fatigue limit value according to the tire's performance.

[0035] Figure 4 is a graph showing an example of the relationship between tire fatigue levels for each tire T1 to T3 and total tire life. In Figure 4, the horizontal axis represents total tire life (time or distance), and the vertical axis represents tire fatigue level.

[0036] As shown in Figure 4, first, a fatigue limit value Ld is set according to the performance of tires T1 to T3. The limit value Ld is set, for example, to correspond to the timing when the case of tires T1 to T3 reaches its usage limit. Then, the fatigue level is quantified according to the usage history (internal temperature, etc.) of tires T1 to T3 since they were installed. Next, the relationship between the fatigue level of tires T1 to T3 and the usage time or mileage (i.e., total tire life) of tires T1 to T3 is graphed. Finally, the remaining durability value is calculated from the graphed relationship. The remaining durability value is expressed as the time or distance from the current fatigue level H of tires T1 to T3 to reaching the limit value Ld. For tires T1 to T3, a steeper slope indicates a smaller remaining durability value, and a smaller slope indicates a larger remaining durability value.

[0037] The fatigue level of a tire may be expressed as a combination of one or more of the following: thermal history (the history of heat the tire has received), internal pressure history (the history of the internal pressure of the tire during use), and acceleration history (the history of the acceleration of the vehicle on which the tire is mounted). The thermal history of a tire can be calculated, for example, based on the temperature history of the tire cavity and / or specific parts of the tire (e.g., belt end, bead area, etc.). For example, the cumulative temperature value during tire use, the time spent at a specific temperature or higher, the highest temperature reached, etc., can be used. It is also possible to calculate the fatigue level based on the rate of temperature change per unit time; in this case, the more rapid the temperature change, the greater the impact on the fatigue level.

[0038] Furthermore, tire pressure, like temperature, is obtained using a sensor (TPMS) attached to the tire. The tire fatigue level can be determined by accumulating and analyzing the history of changes in internal pressure. For example, based on information such as the amount of load applied and for how long, how long the tire was driven with internal pressure outside the appropriate range (too high / too low), and the degree of rapid changes in internal pressure (representing overcoming obstacles, entering potholes, etc.), the amount of damage input to the casing can be calculated, and the tire fatigue level can be calculated considering the durability of the casing.

[0039] Furthermore, acceleration can be obtained and calculated from data from accelerometers mounted on the vehicle, TPMS hub, etc., or from GPS data. Rapid acceleration, sudden braking, and driving speed information can be obtained from changes in longitudinal acceleration. Steering operation history can be obtained from changes in lateral acceleration, and lateral load can be determined based on the number and amount of input. Information such as vertical input due to road surface response during driving and altitude changes when climbing slopes can be obtained from changes in vertical acceleration. By using this information individually or in combination, the amount of damage input to the case can be calculated, and the tire fatigue level can be calculated considering the durability of the case.

[0040] For both internal pressure history and acceleration history, one can choose to either accumulate all tire usage history and analyze that information, or acquire and accumulate information when a standard value is exceeded and analyze that information (in this case, the amount of data can be reduced, leading to reduced computational load and costs). Furthermore, by combining any information, including thermal history, it becomes possible to evaluate tire fatigue in more detail. For example, it is thought that accuracy can be improved by capturing chemical degradation of the rubber using thermal history and physical degradation of the rubber using internal pressure history.

[0041] The determination unit 11C determines whether the tire should be retreaded based on the remaining durability value calculated by the calculation unit 11B and the remaining tire life. The remaining tire life is the remaining time or distance until the tread thickness of the tire becomes less then a predetermined value. Specifically, in the case where the remaining durability > the remaining tire life, until the tire is worn out, durability still remains in the tire, and it is determined that the tire can continue to be used by retreading it. On the other hand, in the case after the remaining durability the other hand, in the case where the remaining durability ≦ the remaining tire life, even if retreading is performed, it is highly possible that the case reaches the usage limit first, so it is determined that it is better to use up the tire without retreading.

[0042] The notification unit 11D notifies the user whether the tire should be retreaded or not from the determination result by the determination unit 11C, for example, via the terminal device 20. The notification method is not particularly limited, but for example, the necessity of retreading may be presented for each tire.

[0043] Here, depending on the remaining degree of remaining durability, the life that can be extended by retreading is also affected, so whether total merits can be obtained by incurring additional costs for retreading becomes the criterion for determination. In this case, the determination unit 11C may acquire the remaining tread thickness, retread life, tire cost, and retread cost, and determine whether the tire should be retreaded based on the remaining durability value, remaining tire life, remaining tread thickness, retread life, tire cost, and retread cost.

[0044] The remaining tread thickness is the tread thickness remaining in the current tire (RTD: Remaining Tread Depth). The retread life is the remaining time or distance until the tread thickness of the tire becomes less than a predetermined value after the tire is retreaded. The tire cost is the cost per tire. The retread cost is the cost of retreading the tire.

[0045] Specifically, the first index value D1 is calculated by the following formula 1. The first index value D1 represents the cost per unit time or unit distance when the tire is used up without retreading.

[0046] D1 = Tire cost / (Time or distance traveled until remaining tread thickness + Remaining tire life) ··· (1)

[0047] Further, the second index value D2 is calculated by the following formula (2). The new tire life is the time or distance until the new tire is worn out, and is preset for each tire. The second index value D2 represents the cost per unit time or unit distance when the tire is retreaded.

[0048] D2 = (Tire cost + Retread cost) / (New tire life + Retread life) ··· (2)

[0049] The first index value D1 and the second index value D2 are compared. If the first index value D1 > the second index value D2, it is determined that retreading should be performed. If the first index value D1 ≤ the second index value D2, it is determined that the tire should be used up without retreading.

[0050] Further, when the determination unit 11E determines that the tire should be retreaded by the determination unit 11C, the determination unit 11E determines the tread thickness for satisfying the retread life from the remaining durability value. Specifically, for example, the determination unit 11E calculates the cost per unit time or unit distance from the remaining durability value, remaining tire life, remaining tread thickness, retread life, tire cost, and retread cost, and determines the retreading timing and tread thickness based on the calculated cost per unit time or unit distance.

[0051] In other words, if the retread life, which is the period during which the retread can be used, can be estimated from the remaining durability value, then it becomes possible to determine the tread thickness necessary to satisfy the estimated retread life. On the other hand, as the tread thickness increases, the retread cost also increases, so the timing and tread thickness of retreading are determined when the second indicator value D2 is, for example, at its minimum. Specifically, the approach differs depending on the average lifespan of new tires and retread tires. For example, by comparing the CPK (cost per unit time or unit distance, hereinafter referred to as "new CPK") of new tires and the CPK (cost per unit time or unit distance, hereinafter referred to as "retread CPK") of retread tires, if new CPK > retread CPK, adjustments are made to use new tires for a longer period and retread tires for a shorter period. On the other hand, if the retreaded tire lifespan is greater than the new tire lifespan, it is more cost-effective to use the retreaded tire for a longer period. Therefore, the optimal values ​​are calculated to determine the timing and retread groove depth, i.e., the tread thickness. In this case, it is assumed that the lifespan of a new tire is less than the total remaining durability of the case.

[0052] Next, with reference to Figure 5, the operation of the retreading determination device 10 included in the retreading determination system 100 according to this embodiment will be explained.

[0053] Figure 5 is a flowchart showing an example of the processing flow by the retreading determination program 15A according to this embodiment.

[0054] When the retreading detection program 15A is instructed to execute, the CPU 11 of the retreading detection device 10 executes the retreading detection program 15A, which is stored in the ROM 12 or memory unit 15, by writing it to the RAM 13.

[0055] In step S101 of Figure 5, the CPU 11 collects usage history data of the tires mounted on the vehicle 21 from the terminal device 20, as shown in Figure 3 above, as an example.

[0056] In step S102, the CPU 11 calculates the remaining durability value using, for example, the correspondence shown in Figure 4 above.

[0057] In step S103, the CPU 11 determines whether or not to retread the tire based on the remaining durability value, remaining tire life, remaining tread thickness, retread life, tire cost, and retread cost. Specifically, for example, the determination is made using equations 1 and 2 described above. If it is determined that the tire should be retreaded (positive determination), the process proceeds to step S104. If it is determined that the tire should be used up without retreading (negative determination), the process proceeds to step S106.

[0058] In step S104, the CPU 11 determines the retreading timing and tread thickness, for example, using equation 2 described above.

[0059] In step S105, the CPU 11 notifies the user, for example, via the terminal device 20, that retreading should be performed, and terminates the series of processes by the retreading determination program 15A.

[0060] On the other hand, in step S106, the CPU 11 notifies the user, for example, via the terminal device 20, that the battery should be used up without retreading, and terminates the series of processes by the retread determination program 15A.

[0061] As described above, according to this embodiment, the remaining durability value is calculated from the relationship between the tire fatigue level accumulated according to the tire usage history data and the total tire life of the tire. Using the calculated remaining durability value, it is possible to appropriately determine whether or not the tire needs to be retreaded.

[0062] Furthermore, the technical scope of this disclosure is not limited to the embodiments described above. Various modifications or improvements can be made to the embodiments without departing from the spirit, and such modified or improved forms are also included within the technical scope of this disclosure.

[0063] The disclosure of Japanese Patent Application No. 2024-195371, filed on 7 November 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A retreading determination device comprising: a collection unit that collects usage history data relating to the usage history of a tire since it was mounted on a vehicle; a calculation unit that calculates a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of fatigue level according to the performance of the tire, based on the relationship between the tire's fatigue level accumulated according to the usage history data and the tire's usage time or mileage; a determination unit that determines whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tire's tread thickness falls below a predetermined value; and a notification unit that notifies whether or not the tire should be retreaded based on the determination result from the determination unit.

2. The determination unit obtains the remaining tread thickness, which is the tread thickness currently remaining on the tire; the retread life, which is the remaining time or distance until the tread thickness of the tire falls below a predetermined value after the tire has been retreaded; the tire cost, which is the cost per tire; and the retread cost, which is the cost of retreading the tire; and determines whether or not the tire should be retreaded based on the remaining durability value, the remaining tire life, the remaining tread thickness, the retread life, the tire cost, and the retread cost, the retread determination device according to claim 1.

3. The retread determination device according to claim 2, further comprising a determination unit that determines, based on the remaining durability value, the tread thickness necessary to satisfy the retread life when the determination unit determines that the tire should be retreaded.

4. The retread determination device according to claim 3, wherein the determination unit calculates the cost per unit time or unit distance from the remaining durability value, the remaining tire life, the remaining tread thickness, the retread life, the tire cost, and the retread cost, and determines the timing of the retread and the tread thickness based on the calculated cost per unit time or unit distance.

5. A retreading determination method in which a computer performs the following processes: collects usage history data relating to the usage history of a tire since it was mounted on a vehicle; calculates a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of fatigue level according to the tire's performance, based on the relationship between the tire's fatigue level accumulated according to the usage history data and the tire's usage time or mileage; determines whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tire's tread thickness falls below a predetermined value; and notifies whether or not the tire should be retreaded based on the determination result.

6. A retreading determination program that causes a computer to perform the following processes: collect usage history data relating to the usage history of a tire since it was mounted on a vehicle; calculate a remaining durability value, which is the time or distance until the current fatigue level of the tire reaches a predetermined limit value of fatigue level according to the tire's performance, based on the relationship between the tire's fatigue level accumulated according to the usage history data and the tire's usage time or mileage; determine whether or not the tire should be retreaded based on the remaining durability value and the remaining tire life, which is the time or distance until the tire's tread thickness falls below a predetermined value; and notify the computer whether or not the tire should be retreaded based on the determination result.

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